1. Field of the Invention
The present invention relates generally to the structure of sorting conveyors. More specifically, the invention relates to an improved structure of conveyors having laterally deflectable article transporting pallets.
2. Description of the Prior Art
The use and design of sorting conveyors of the type consisting of deflectable article carrying sliders mounted on slide rods fixed at each end to an advancing chain is well known. Typical conveyors of this type are disclosed in U.S. Pat. Nos. 3,731,782; 3,500,983; 3,190,432; 3,167,171; 3,129,803; 3,093,245; and 3,009,572. Various advances in the conveyor art have been made which have improved the reliability of these devices and which have enabled the increase of number of articles per minute capable of being handled by the devices. However, one substantial limitation of the prior art devices has remained until the advancement of the present invention.
State-of-the-art conveyors of the type having deflectable article carrying sliders mounted on slide rods are disadvantaged by the fact that they are incapable of operating faultlessly when they are required to convey and sort heavy articles, especially at higher throughputs. It is believed that the major cause of this disability is that the increased weight of the conveyed articles causes the slide rods to bow, thereby making deflection of the sliders along the slide rods more difficult. This difficulty is aggravated by the increase of friction between the slider and the slide rod which results from the increased weight of the conveyed articles and which further impedes the deflection of the slider. Finally, in those conveyors exemplified by U.S. Pat. Nos. 3,731,782 and 3,167,171 in which a magnetic device is utilized to cause switching of magnetically attractable sliders as well as to cause the sliders to follow a given path, the resistance effects of additional momentum of the heavier articles as well as the previously discussed effects of increased friction and slide rod bowing tend to contribute to a condition which frequently exceeds the ability of the magnetic devices to attract and hold the magnetically attractable slider. In this event, either the switching operation is not effectively completed or the slider breaks away from the desired path prematurely so that the sorting conveyor is ineffectual for accomplishing its sorting function.